Assessment of lesion insertion tool in pelvis PET/MR data with applications to attenuation correction method...

Area of Science:

• Medical Imaging
• Positron Emission Tomography (PET)
• Image Reconstruction

Background:

• Attenuation correction (AC) is crucial for accurate quantitative analysis in multi-modality PET imaging (PET/CT, PET/MR).
• Software-based simulation tools, like lesion insertion tools, require extensive validation for clinical relevance.
• Assessing AC methods and reconstruction parameters necessitates reliable simulation environments.

Purpose of the Study:

• To evaluate different PET attenuation correction (AC) methods using a synthetic lesion insertion tool.
• To simulate lesions in a patient cohort with both PET/MR and PET/CT images.
• To demonstrate the utility of lesion insertion tools for understanding PET reconstruction parameters beyond AC.

Main Methods:

• Compared lesion quantitation using MR-based AC (MRAC) against CT-based AC (CTAC) as ground truth.
• Simulated 71 pre-existing lesions in pelvic PET/MR images and inserted matched lesions contralaterally.
• Inserted synthetic lesions into four target locations in four patients without observed pelvic lesions.

Main Results:

• Matched lesion insertions showed high agreement in lesion error ratios (mean SUVs), validating simulation accuracy.
• Inserted lesions exhibited distinct characteristics based on target locations.
• Observed negative trends in maximum SUV differences for bone-dominant sites.

Conclusions:

• The lesion insertion tool effectively simulates pelvic lesions and their SUV values.
• This tool can be extended to assess various PET reconstruction corrections and algorithms.
• The validated tool enhances the evaluation of quantitation accuracy and precision in PET imaging.